Bio-efficacy of the Essential Oil of Oregano (<Emphasis Type="Italic">Origanum vulgare</Emphasis> Lamiaceae. Ssp. <Emphasis Type="Italic">Hirtum</Emphasis>)

The aim of this study was to investigate the bioactivity of the essential oil isolated from Origanum vulgare L. (EOv). We analyzed the in vivo anti-inflammatory properties in a mouse-airway inflammation model and the in vitro antimicrobial activity, genotoxicity over the anaphase-telophase with the Allium cepa strain and its cytotoxicity/viability in A549 culture cells. In vivo, EOv modified the levels of tumor necrosis factor -α and viable activated macrophages and was capable to mitigate the effects of degradation of conjugated dienes. In vitro, EOv reduced the viability of cultured A549 cells as well as the mitotic index and a number of chromosomal aberrations; however, it did not change the number of phases. We found that EOv presents antimicrobial activity against different Gram (?) and (+) strains, measured by disc-diffusion test and confirmed with a more accurate method, the AutoCad software. We postulate that EOv presents antibacterial, antioxidant and chemopreventive properties and could be play an important role as bioprotector agent.     

Assessing the effects of subtropical forest fragmentation on leaf nitrogen distribution using remote sensing data

Subtropical forest loss resulting from conversion of forest to other land-cover types such as grassland, secondary forest, subsistence crop farms and small forest patches affects leaf nitrogen (N) stocks in the landscape. This study explores the utility of new remote sensing tools to model the spatial distribution of leaf N concentration in a forested landscape undergoing deforestation in KwaZulu-Natal, South Africa. Leaf N was mapped using models developed from RapidEye imagery; a relatively new space-borne multispectral sensor. RapidEye consists of five spectral bands in the visible to near infra-red (NIR) and has a spatial resolution of 5 m. MERIS terrestrial chlorophyll index derived from the RapidEye explained 50 % of the variance in leaf N across different land-cover types with a model standard error of prediction of 29 % (i.e. of the observed mean leaf N) when assessed on an independent test data. The results showed that indigenous forest fragmentation leads to significant losses in leaf N as most of the land-cover types (e.g. grasslands and subsistence farmlands) resulting from forest degradation showed lower leaf N when compared to the original indigenous forest. Further analysis of the spatial variation of leaf N revealed an autocorrelation distance of about 50 m for leaf N in the fragmented landscape, a scale corresponding to the average dimension of subsistence fields (2,781 m²) in the region. The availability of new multispectral sensors such as RapidEye thus, moves remote sensing closer to widespread monitoring of the effect of tropical forest degradation on leaf N distribution.     

Factors underlying farm diversification: the case of Western Australia’s olive farmers

The growth of niche markets in rural industries has been one response to the restructuring of established agricultural industries in developed countries. In some cases entry into niche markets is part of a diversification of activities from other areas of farm-based production or services. In other cases, operators have sought to diversify from niche market production into other areas, such as on-site selling and agritourism. This paper outlines the findings of an exploratory qualitative study of the factors that olive farmers in Western Australia take into account when considering diversification, with a special focus on diversification into servicing visitors in the form of on-site selling and agritourism. Face-to-face and telephone interviews were conducted among 23 small olive growing operations located in the main olive growing region of Western Australia. Decision-making is shown to involve an assessment of risk, which is shaped by their appraisal of economic conditions, market opportunities, access to resources (including labor), and lifestyle factors. The argument is made that a fuller understanding of diversification is gained by studying both those who seek to diversify and those who do not, in contrast to most previous research that has only focussed on those who diversify. Also argued is that diversification is best seen as a continuum of adjustment strategies, which is guided by a combination of economic need, risk assessment (based largely on resource access), market potential, and lifestyle factors.     

Variation in soil properties in a transformed ecosystem in Southwestern Nigeria

Variation in soil properties as a result of the conversion of the tropical rainforest to a monospecific plantation of teak, tectona grandis, was examined in Akure forest reserve in Southwestern Nigeria. Comparison was made in the active rooting zone of 50 cm soil depth. It was discovered that there were no significant differences in the physical properties except in the value of organic matter content at the top 10 cm layer but chemical properties such as the pH and organic carbon changed significantly at the top 10 cm layer. Differences in other chemical properties, such as the available P, exchangeable cations K, Ca and Mg, the exchangeable acidity and the cation exchange capacity were minor. This showed that no nutrient was limiting or was likely to be limiting in the soil for subsequent short rotation of plantation development.     

Assessment of cold tolerance at early developmental stages and allelic variation at candidate genes in South American rice germplasm

Rice is susceptible to cold during early developmental stages. Most tolerant cultivars have been developed for other conditions than those occurring in South America’s rice growing areas, or their grain type is not suitable for the local markets. If locally adapted varieties were available, growers could anticipate sowing date, making flowering time coincide with the moment of maximum solar radiation and increasing yields. In this work, 116 rice inbred lines and varieties of diverse origin within the South American gene pool were tested for seedling survival and germination percentage under low temperature in controlled conditions. As a result, lines used as controls responded as expected, whereas lines with similar behavior to controls, intermediate between susceptible and tolerant controls and more extreme than controls were detected at both seedling and germination stages. Allelic variation at candidate genes OsGSTZ1, OsGSTZ2 and OsCDPK13 was analyzed in a subset of ten contrasting lines. Ten out of thirty-four polymorphisms detected in all three genes were associated with cold tolerance in these lines. A functional marker, designed from an aminoacid-changing SNP found in gene OsGSTZ2, was tested in the 116 lines. As a result, a tight association was observed between cold tolerance and marker score. In conclusion, wide variability for cold tolerance at early developmental stages has been detected in rice advanced breeding materials that are adapted to local growing conditions. Also, a functional marker tightly associated with the trait is available for performing marker assisted selection.     

Potential of genomic selection in rapeseed (Brassica napus L.) breeding

Genomic selection employs genome‐wide marker data to predict genomic breeding values. In this study, a population consisting of 391 lines of elite winter oilseed rape derived from nine families was used to evaluate the prospects of genomic selection in rapeseed breeding. All lines have been phenotyped for six morphological, quality‐ and yield‐related traits and genotyped with genome‐wide SNP markers. We used ridge regression best linear unbiased prediction in combination with cross‐validation and obtained medium to high prediction accuracies for the studied traits. Our results illustrate that among‐family variance contributes to the prediction accuracy and can lead to an overestimation of the prospects of genomic selection within single segregating families. We also tested a scenario where estimation of effects was carried out without individuals from the family in which breeding values were predicted, which yielded lower but nevertheless attractive prediction accuracies. Taken together, our results suggest that genomic selection can be a valuable genomic approach for complex agronomic traits towards a knowledge‐based breeding in rapeseed.